“The universe is either deterministic or it isn’t. This has nothing to do with free will. We have it.”
This is correct, except for the third sentence, which should read “We have it, as long as you redefine it as consisting of properties we have.” Preserving a folk concept like ‘free will’ and recasting it as “reasons responsiveness” (or whatever) in order to confirm that actually, we do have free will seems like the epitome of a pointless equivocation. (Cf. “We have free markets; it’s just that they’re centrally planned.”)
“To be is to be the value of a bound variable.”
No. To be a justified existential postulate is to be the value of a bound variable. (Cf. your subsequent musings about epistemology.)
“Modal statements about fundamental kinds (”gold might have had a different atomic weight”) may be grammatical but are not meaningful.”
Only if we insist on reading it in terms of the Kripkean construction that gold necessarily has the atomic weight that it does. (Again, cf. your remarks on epistemology.)